1. Field of the Invention
The present invention relates to heat dissipation assemblies for heat-generating electronic apparatuses such as those used in computers, and more particularly to a heat dissipation assembly which allows a heat sink and a clip thereof to be combined together in advance.
2. Description of Related Art
A computer central processing unit (CPU) is the core administrator of electrical signals in most contemporary personal computers. Continued development of CPUs has enabled them to perform more and more functions. Heat generated by CPUs has increased commensurately. If excessive heat is generated, this can adversely affect the operational stability of computers. Measures must be taken to efficiently remove the heat from the CPU. Typically, a heat dissipation device having great heat conductivity is mounted on the CPU to remove heat therefrom. A clip is frequently used to firmly attach the heat dissipation device to the CPU, thus achieving greater efficiency of heat dissipation.
A conventional clip for fastening a heat dissipation device to a CPU is an elongate plate that is bent to have a generally M-shaped profile, as shown in U.S. Pat. No. 6,343,015 B1 and Taiwan Patent No. 89216225. The clip defines opposite slots that engagingly receive ears of a socket on which the CPU is mounted. The clip thereby attaches a heat-conducting portion of the heat dissipation device to an upper surface of the CPU. However, such clips are made from plate material, which is bulkier and more expensive than thread, rod or wirelike material. Furthermore, space must be reserved on the heat dissipation device for receiving the clip. A plate-like clip needs more reserved space on the heat sink compared with a thread, rod or wirelike clip. The unduly large reserved space reduces the number of fins that can be configured on the heat dissipation device. This reduces the efficiency of heat dissipation.
Taiwan Patents Nos. 87218994 and 87205513 disclose another kind of clip developed to overcome the above-mentioned problems. The clip is made from an elongated thread or rod of wire or suitable wirelike material. Unfortunately, the clip and the heat dissipation device are independent parts that cannot be attached together in advance. Therefore transportation of the heat dissipation device is inconvenient and unduly costly. Another disadvantage is that during installation of the heat dissipation device on a CPU mounted on a printed circuit board (PCB), the clip must be manually manipulated beside the CPU. Because space around the PCB is generally very limited, it is difficult to manipulate the clip, and there is an appreciable risk of accidentally damaging the CPU. Moreover, all these difficulties render mass production of goods incorporating the heat dissipation device inconvenient, slow and unduly costly. U.S. Pat. Nos. 5,331,507 and 5,615,735 also disclose some wire-like retainer for use with the heat sink on the CPU device.
Accordingly, an object of the present invention is to provide an inexpensive heat dissipation assembly which allows a heat sink and a clip thereof to be conveniently combined together in advance.
In order to achieve the object set out above, a heat dissipation assembly of the present invention includes a fan, a mounting bracket, a clip, a heat sink and a mounting frame. The mounting bracket includes a top plate, and two sideplates depending from opposite sides of the top plate respectively. The fan is mounted to the mounting bracket. The clip is bent from an elongated thread or rod of wire or suitable wirelike material. The clip includes a central horizontal part, and a pair of resilient arms extending perpendicularly from opposite ends of the horizontal part respectively. A hook extends inwardly from a top of each resilient arm. A groove is laterally defined through the heat sink fins, and receives the horizontal part of the clip therein. The combined fan and mounting bracket is attached to the combined heat sink and clip to form a subassembly. Thus, the clip is secured in the heat sink in advance. The mounting frame is attached to a printed circuit board (PCB), and surrounds an electronic package that is also attached to the PCB. Two spaced protrusions extend upwardly from each of opposite sides of the mounting frame. An aperture is defined in a distal end of each protrusion. The subassembly is received in the mounting frame, with the heat sink contacting the electronic package. Two of the apertures of the mounting frame respectively engagingly receive the hooks of the clip. Thus, the heat dissipation assembly is fully assembled.
Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: